diff --git a/kernel/rtlil_bufnorm.cc b/kernel/rtlil_bufnorm.cc
index e2d0eae9f..63e9c7c46 100644
--- a/kernel/rtlil_bufnorm.cc
+++ b/kernel/rtlil_bufnorm.cc
@@ -1057,7 +1057,7 @@ void RTLIL::Cell::unsetPort(const RTLIL::IdString& portname)
 void RTLIL::Cell::setPort(const RTLIL::IdString& portname, RTLIL::SigSpec signal)
 {
 	bool is_input_port = false;
-	if (module->sig_norm_index != nullptr && type != ID($specify2)) {
+	if (module->sig_norm_index != nullptr && type != ID($specify2) && type != ID($specify3) && type != ID($specrule)) {
 		module->sig_norm_index->sigmap.apply(signal);
 		auto dir = port_dir(portname);